1. Field of the Invention
The present invention relates to a glass, a glass material for press molding, an optical element blank, and an optical element. More particularly, the present invention relates to a glass that has a refractive index nd ranging from 1.790 to 1.830 and an Abbe's number vd ranging from 45 to 48, a glass material for press molding, an optical element blank, and an optical element which are formed of this glass.
2. Description of Related Art
As an optical element material constituting an optical system, for example, an imaging optical system such as a camera lens or a projection optical system such as a projector, a high refractive index and low dispersion optical glass having a refractive index nd ranging from 1.790 to 1.830 and an Abbe's number vd ranging from 45 to 48 is known (e.g. see Patent Documents 1 to 6). In the following description, the refractive index and the Abbe's number refer to a refractive index nd for a line d and the Abbe's number vd for the line d, respectively, unless otherwise specified.